Fire extinguisher



United States Patent FIRE EXTINGUISHER Ralph W. Austin, Weymouth, Mass.,assignor to Process Engineering Inc., Somerville, Mass., a corporationof Massachusetts Application April 11, 1955, Serial No. 500,324

2 Claims. (Cl. 169-31) This invention relates to a fire extinguisher.

In general the object of the invention is to provide a novel and highlyetficient fire extinguisher of the type wherein an extinguishing mediumis expelled from the extinguisher casing by gas pressure released from apressurized sealed cartridge by puncturing the cartridge when theextinguisher is to be operated. The invention contemplates anextinguisher which is simple in construction, may be economicallymanufactured and recharged in a simple manner and in a minimum of time.

With this general object in view and such others as may hereinafterappear the invention consists in the fire extinguisher and in thevarious structures, arrangements and combinations of parts hereinafterdescribed and particularly defined in the claims at the end of thisspecification.

In the drawings, the figure is a vertical elevation with portions insection illustrated in the preferred embodiment of the presentinvention.

The present invention contemplates an improved fire extinguisher of thetype in which an extinguishing medium is expelled from the extinguishercasing by gas pressure released from a pressurized sealed cartridge.Provision is made for supporting the cartridge in a novel and improvedmanner and for insuring a free flow of the pressurized gas from withinthe cartridge to within the extinguisher casing.

Referring now to the drawing, represents the extinguisher casing havinga threaded neck portion 12. A cap 14 provided with threads 16 is screwedon the threads 18 in neck portion 12 to close and seal the same.Provision is made for supporting a sealed pressurized cartridge 36containing, for example, a supply of carbon dioxide in the form of DryIce under pressure Within the upper portion of the extinguisher casing.Piercing mechanism is supported within the cap 14 for piercing thepressurized cartridge 36 when it is desired to operate the extinguisher.

As illustrated in the drawing, the upper portion of the cap 14 isprovided with upstanding portion 20 having an internally threadedportion as at 22 into which an externally threaded plug 24 is screwed toclamp a flange 25 of a resilient rubber plunger 30 against the interiorof the portion 20 of the cap. The upper end of the plunger 30 isarranged to extend upwardly through a hole in upstanding portion 20 toproject above the upper surface thereof, and above the usual handle onthe extinguisher casing as shown. The rubber plunger 30 is provided witha longitudinally extended metal puncture pin 32 molded therein, thelower end of which is sharply pointed and extends a predetermineddistance into the neck portion 12 of the extinguisher casing 10 when thecap 14 is screwed tightly upon said neck 12.

The cartridge 36 is preferably provided with a cylindrical body portion38 open at one end 40 and is further provided with an integral flangeportion 42 adjacent its open upper end. The upper portion of flange 42is provided with an outwardly turned integral annular rim 43 arranged tobe seated upon the rim of neck 12, as shown,

and in this manner container 36 is suspended within casing 10. Provisionis made for attaining a tight seal between cap 14 and rim 43 comprisingan annular washer of any suitable material, such as rubber or the like,superimposed upon said rim 43 and compressed thereagainst by the bottomsurface of cap 12 when said cap is screwed tightly upon the neck ofcasing 10. In practice the cartridge is filled With a supply of Dry Iceand sealed by cap 46 welded to the upper open end thereof, as shown.

The top portion 52 of the cap 46 is preferably of relatively thin,puncturable material which may be easily perforated by puncture pin 32when it is desired to operate the extinguisher.

In order to provide and maintain a free flow of gas from within thecartridge 36 to be metered into the extinguisher casing to pressurizethe same a cup-shaped metering disk 50 is welded within the cap 46 withits open end adjacent the thin, puncturable top portion 52 of said cap46. The metering disk 50 is provided in its bottom with a metering holewhich is generally funnelshaped in section having the wider end 54 ofthe metering opening centered within the cap 46, the narrow end 56 beingspaced a short distance upwardly therefrom. The narrow portion 56 ofsaid hole may be of any desired size and preferably will be of a sizeequivalent to the hole formed with a No. 77 drill and is centereddirectly beneath and in alignment with the pointed tip of puncture pin32. In order to prevent impurities from clogging the narrow portion 56of the meter hole a wire mesh screen 58 of a size suflicient tocompletely extend across and cover the interior of the cap is welded tothe interior walls thereof immediately below metering disk 56 between itand the interior of cartridge 36.

One of the principal difliculties which is encountered in the operationof the fire extinguishers of this general type now on the market hasbeen that impurities, which may be found in the gas generating chemicalsthemselves or may be small particles of carbon dioxide in its solidform, are deposited upon the surface of the filtering screen, thoroughlyclogging the same. The prior art metering disk now found in varioustypes of extinguishers on the market is usually a fiat disk having themetering hole drilled in the center thereof, and a filtering screen offine mesh is positioned adjacent said disk between it and the gasgenerating chemical container. In practice when the gas generatingchemical container is punctured and gas released the pressure of theescaping gas forces the filtering screen against the disk, and anyparticles deposited on said screen partially or totally clog the hole,hnpairing or destroying the efiiciency of the extinguisher. This isparticularly true because of the small size of said metering hole.

In accordance with the present invention the tendency of the filteringscreen to become clogged is substantially eliminated by the particularstructure and arrangement of the present metering disk 50 and thelocation of the metering hole with relation to the fine wire meshfiltering screen 58. It will be observed that when the puncturable top52 of the cap 46 is punctured by puncture pin 32 in the mannerhereinafter to be described, the escaping gas from within the body ofthe cartridge 35 will cause filter screen 58 to move upwardly againstthe wider part of the funnel-shaped metering hole. In practice the areaof said wide portion or entrance 54 of the metering hole is ofsuificient size to permit a normal quantity of impurities to collect on"the screen 58 and still be of sufiicient diameter to permit the gas topass freely therethrough to be metered through the metering aperture andinto the interior of the extinguisher casing.

In order to allow the metered flow of gas flowing 3 through meteringdisk 50 to enter the body of the extinguisher casing to pressurize thesame, flange 42 is provided with a plurality of spaced openings 60communicating with the interior of casing 10.

In operation when it is necessary to operate the present extinguisher,the rubber plunger 30 is depressed either by hand pressure or may beeasily operated by inverting the entire casing and striking the top ofplunger 30 in contact with a solid surface. The weight of the casing ofitself may be suflicient to depress the plunger 30, causing pin 32 topierce the frangible top of the cap 46 and to thus release the pressurefrom within cartridge 36. When such pressure is released the plungerwill, due to its resiliency, return pin 32 to its normal position. WhenDry Ice is utilized as the gas generating medium the sudden release ofpressure causes it to react to attain its normal gaseous state. Such gaswill then flow through screen 58, metering disk 50 and into the area 61beneath extinguisher casing cap 14 and flange 42 to thereafter flowthrough openings 60 in said flange into the body of casing 10,pressurizing the same in a very even, rapid manner.

In practice the body of the extinguisher casing may be filled with anyknown extinguishing fluid, such as Water and the like, as illustrated inthe drawing at 65. Provision is made for directing a stream of suchfluid onto a fire when the extinguisher is put in operation and the bodypressurized, as hereintofore described, including an outlet 66 formed inthe upper end of casing 10, as shown, provided with a suitable coupling68 to which a hose 70 and nozzle 72 may be connected in any usualmanner. In order to prevent sediment or other impurities from cloggingthe outlet 66, hose and nozzle 70, 72 and a filter screen 74 of any typefound on the market are preferably secured to the casing Wall coveringsaid outlet 66, as shown.

From the foregoing description it will be apparent that the present fireextinguisher may be maintained in perfect operating condition for longperiods of time by recharging and may be quickly and efiicientlyrefilled and recharged in a simple, economical manner. A plurality ofgas generating cartridges 36 may be kept on hand, and during a fire theextinguisher may be quickly recharged and used a number of times byquickly changing the containers and refilling the casing with water orother fluid.

Having thus described the invention, what is claimed 1. A fireextinguisher comprising an extinguisher casing having an opening in theupper end thereof and an externally threaded neck surrounding theopening, said casing containing a body of extinguishing medium and beingprovided with an outlet, a cap screwed upon the threaded neck closingthe opening in the'easing, a puncturable pressurized cartridgeoperatively supported within the casing a short distance below the cap,a resiliently mounted puncturing member operatively supported-in the capand adapted when depressed to puncture said pressurized cartridge, saidcartridge comprising a body portion and a cup-shaped cap member weldedto the body portion and having a cup-shaped screen welded to theinterior of the cap and extending across the same, and a cup-shapedmetering member also welded to the interior of the cap and provided withan upwardly tapering opening therein disposed between the screen and thepuncturable top of the cartridge.

2. A fire extinguisher comprising an extinguisher casing open at oneend, a cap for detachably closing said opening, manually operatedpuncturing means carried by,

the cap, an extinguisher medium within said casing, a container for asupply of pressurizing medium having means integral therewith forsuspending said container within the body of the extinguisher casingincluding an annular flange having a plurality of openings therein, anannular rim adapted to be detachably supported upon the open end of thecasing and secured in position by the,

References Cited in the file of this patent UNITED STATES PATENTS HeigisJuly 25, 1933 Allen Sept. 16, 1952

